Biochar alters hydraulic conductivity and impacts nutrient leaching in two agricultural soils

• DOI: 10.5194/soil-7-811-2021
• Publication Date: 2021-12-21T06:40:28Z
• Authors: Danielle L. Gelardi; Irfan H. Ainuddin; Devin A. Rippner; Janis E. Patiño; Majdi Abou Najm; Sanjai J. Parikh
• Keywords: Cation-exchange capacity

Abstract. Biochar is purported to provide agricultural benefits when added the soil, through changes in saturated hydraulic conductivity (Ksat) and increased nutrient retention chemical or physical means. Despite interest investigation, there remains uncertainty regarding ability of biochar deliver these agronomic due differences feedstock, production method, temperature, soil texture. In this project, a suite experiments was carried out using biochars diverse feedstocks temperatures, order determine parameters which may optimize benefits. Sorption were performed with seven distinct sorption efficiencies for ammonium nitrate. Only one effectively retained nitrate, while all bound ammonium. The three highest binding capacities (produced from almond shell at 500 800 ∘C (AS500 AS800) softwood (SW500)) chosen column experiments. Biochars amended sandy loam silt 0 % 2 (w/w), Ksat measured. reduced both soils by 64 %–80 %, exception AS800, 98 loam. Breakthrough curves nitrate ammonium, as well leachate concentration, also measured columns. All significantly decreased quantity leachate, 22 78 slowed its movement profile. Ammonium linked high cation exchange capacity oxygen-to-carbon ratio, indicating that primary control biochar-amended affinity between surfaces had little no effect on timing release, only SW500 total quantity, 27 36 %. retain be micropore specific surface area, suggesting entrapment rather than binding. Together, work sheds new light combined means alter impact leaching production.